package demo1;


import javax.management.remote.rmi._RMIConnection_Stub;
import java.util.Arrays;
import java.util.Objects;

public class HashBuck2<K,V> {
    static class Node<K,V> {
        public K key;
        public V val;

        public Node<K,V>next;

        public Node(K key,V val) {
            this.key = key;
            this.val = val;
        }
    }

    public Node<K,V>[] array;
    public int usedSize;
    public static final float DEFAULT_LOAD_FACTOR = 0.75f;

    public HashBuck2() {
        array = (Node<K, V>[]) new Node[10];
    }

    public void put(K key,V val) {
        int hash = key.hashCode();
        int index = hash%array.length;

        Node<K,V> cur = array[index];
        while(cur!=null) {
            if(cur.key.equals(key)) {
                cur.val = val;
                return;
            }
            cur = cur.next;
        }

        Node<K,V> node = new Node(key,val);
        node.next = array[index];
        array[index] = node;
        usedSize++;

        //resize()
        if(doLoadFactor() > DEFAULT_LOAD_FACTOR) {
            resize();
            System.out.println("resize()");
        }
    }

    public float doLoadFactor() {
        return usedSize*1.0f/array.length;
    }

    public void resize() {
        Node<K,V>[] tmpArray = Arrays.copyOf(array,array.length*2);

        for(int i = 0;i<array.length;i++) {
            Node<K,V> cur = array[i];
            while(cur!=null) {
                Node<K,V> next = cur.next;
                int hash = cur.key.hashCode();
                int newIndex = hash%tmpArray.length;
                cur.next = tmpArray[newIndex];
                tmpArray[newIndex] = cur;
                cur = next;
            }
        }

        array = tmpArray;
    }

    public V getValue(K key) {
        int hash = key.hashCode();
        int index = hash%array.length;
        Node<K,V> cur = array[index];
        while(cur!=null) {
            if(cur.key.equals(key)) {
                return cur.val;
            }
            cur = cur.next;
        }
        return null;
    }


}
